The invention relates to the field of washing equipment and washing fluid reclamation; more particularly, it relates to a tortuous path filter for sedimentation and clarification of washing fluids, and to an optional sump and solid waste discharge.
In the vehicle repair and maintenance industry, as well as in other industries in which equipment and parts become dirty and/or greasy, such as for military weapons maintenance, it is common to employ some kind of washing apparatus for dirty parts and assemblies and some kind of cleaning fluid or solvent for use in the washing equipment. Typically the fluid is expensive, especially for fluids optimized for environmental impact and for safety and health of workers. It is thus advantageous to be able to reuse and/or recycle such fluid.
During the degreasing and cleaning process in the parts washer, the cleaning fluid invariably becomes contaminated with larger and smaller particles of dirt and worn metal and globules of heavier greases and oils. To maintain the cleaning effectiveness of the fluid it is considered essential to filter out or otherwise remove from time to time some or all of such contaminants from the fluid.
Some parts washers are equipped with means to filter and/or distill the cleaning fluid and thus separate the contaminants, either continuously or in a batch process during down time. Examples include the System One 500 Series parts washer from Mansur Industries in Miami, Fla., and TranSolv""s Model CH solvent recycler. However, direct filtering of contaminated washing fluid generally causes premature overload of filter canisters, necessitating frequent replacement of the canisters. Other washing installations employ separate distillation equipment. Some sites employ mobile fluid recycling services who, either on or off site, filter and/or distill the cleaning fluid from the on site parts washers. The Zymo company even provides a parts washer with built in bioremediatioin of the cleaning fluid, while another company provides a built in centrifugation system to filter out contaminants. All of these fluid recovery or recycling processes are expensive and laborious, and many of them require considerable down time for each parts washer while the fluid is cleaned.
What is needed is a solvent recycling system that is inexpensive in operation, labor free, requires little or no down time in operation, and is safe for workers and for the environment, with minimal need for, or long intervals between, solvent and/or canister filter replacement.
Accordingly, it is an object of the invention to provide a solvent recycling system that is inexpensive in operation, labor free, requires little or no down time in operation, and is safe for workers and for the environment, with minimal need for, or long intervals between, solvent, and/or canister filter replacement.
It is a further object of the invention to provide a filtering stage for a multistage filtering system that will inhibit clogging of finer downstream filters.
It is another object of the invention to provide a settling tank for clarifying washing fluids with a wall disposed within the tank, the wall having a plurality of passages and defining a settling chamber.
It is another object of the invention to provide a settling tank with a top mounted fluid runoff opening into the tank disposed above a settling chamber and at least one pump inlet disposed in an upper part of the tank outside the settling chamber.
It is a further object of the invention to provide a settling tank with an inner wall defining a central settling chamber and a second wall surrounding the inner wall and defining a second settling chamber between the inner wall and the second wall, each wall having a plurality of passages and with the pump inlet disposed outside the second wall.
It is another object of the invention to provide a settling tank with the passages in the inner wall in a lower region of the wall, and the passages in the second wall in an upper region of the wall, with at least some of the passages hooded to enhance a flow velocity change for fluid passing through the passages.
It is a further object of the invention to provide a settling tank with a sump pump having a one way valve for discharging sump sediment from the sump into a portable waste can.
It is a further object of the invention to provide a fluid pump connected to the pump inlet, with the pump controlled to operate only during fluid runoff into the tank, the better to enhance settling of particles and heavier greases and oils during periods when the washer is not in use.
It is yet another object of the invention to meet any or all of the needs summarized above.
These and such other objects of the invention as will become evident from the disclosure below are met by the invention disclosed herein.
The invention addresses and provides such a system. The invention represents the only parts washer with built in low cost solvent recycling by means of a tortuous path, multichambered settling tank, whereby sludge and other settled contaminants may be removed without removing the fluid from the washer and without substantial interruption to the operating cycle of the washer.
In one aspect of the invention there is a settling tank for clarifying washing fluids. There is preferably at least one wall disposed within the tank, the wall having a plurality of passages therethrough. The wall may be further comprised of wall pieces joined together with appropriate angles and seams, or it may be a substantially single piece folded or bent appropriately, in either case so to define at least one separate settling chamber within the settling tank. The walls of the settling tank and of the settling chamber(s) are preferably substantially vertical, or at least funnel or cone shaped. The settling chamber wall(s) preferably run in height from a point at or above an upper fluid fill limit line in the settling tank to point(s) at or just above respective line(s) at which the plane(s) of the settling chamber wall(s) intersect the wall(s) of the settling tank, or, if optionally provided, the settling tank bottom.
Preferably there is a top mounted fluid runoff opening into the settling tank disposed generally and substantially above the settling chamber, or the central most settling chamber if there are more than one. In preferred embodiments, the fluid runoff is a perforated drain plate that is in fluid communication with a washing surface above the settling tank. Preferably there is also at least one pump inlet disposed preferably in an upper part of the settling tank outside any of the settling chambers. In preferred embodiments there is more than one settling chamber, with an inner wall defining a central settling chamber and a second wall surrounding the inner wall and defining a second settling chamber between the inner wall and the second wall. A referred embodiment is thus a nested settling chamber arrangement, where no settling chamber wall is coplanar with or touching any other settling chamber wall, or the settling tank wall. It will be appreciated however that other embodiments, including those with settling chamber walls touching or in common with each other or with the settling tank, or with non nested, non symmetrical, and/or non centered settling chambers, may also be employed to some particular advantage without departing from the scope of the invention.
As above, each settling chamber wall preferably has a plurality of passages therethrough, each passage in fluid communication with the settling chamber defined by its wall and with the next most outer settling chamber or settling tank respectively. Where there is more than one settling chamber, any pump inlets are preferably disposed outside the outermost settling chamber wall.
Preferably the passages in the innermost settling chamber wall are in a lower region of the wall, and the passages in the second, or nextmost, inner, settling chamber wall are in an upper region of the wall, and so forth in alternation for each successive nextmost inner settling chamber wall, in order best to extend a flow path for the sediment carrying fluid from its entrance into the settling tank to its eventual pickup at one of the pump inlets. Alternatively, the passages in the innermost settling chamber wall may be in an upper region of the wall, and the passages in the second, or nextmost inner, settling chamber wall may be in a lower region of the wall.
At least some of the passages referred to above are preferably hooded, or otherwise partially flow shielded, to enhance a flow velocity change for fluid passing through the passages. Such hooded passages may advantageously employ an anti-flow facing hooded, or an anti-flow oriental tubing, or the like. Preferably the second, or outermost settling chamber, wall is devoid of passages in a blank region of the wall facing, or most proximate, the pump inlet.
Preferably there is also a set off between a bottom of one or more of the walls and the tank to allow settling contaminants in the tank and in outer settling chambers to have a settling path to the sump. The tank is also preferably substantially funnel shaped to enhance contaminant sliding to the sump, the funnel being any of several possible shapes including conical and also square or flat sided. The tank further has a sediment holding sump disposed at a bottom part of the tank substantially beneath a settling chamber, and preferably beneath the centralmost settling chamber. The sump is also preferably substantially funnel shaped.
There is also provided a sump pump having a one way valve for discharging sump sediment from the sump into a portable waste can. The sump pump may advantageously be a simple manual suction pump, or may be an electric or other powered sediment pump. To enhance sediment withdrawal and conserve fluid loss, there is also preferably a sump tube generally curved upwardly and away from a bottom of the sump, and to which the sediment pump is connected.
Preferred embodiments will have a fluid pump connected to the pump inlet, with the pump controlled to operate only during fluid runoff into the tank (that is, during washing as fluid and contaminants pass through the drain from a washing surface and down into the settling tank), the better to enhance settling of particles and heavier greases and oils during periods when the associated washer is not in use.
There is optionally provided a constant pressure washer outlet apparatus comprising a reservoir (preferably in the form of a settling tank), a pump, a conventional canister type filter and a washer outlet, all connected for fluid flow therethrough from the reservoir on through the washer outlet, and further comprising a bypass valve between the filter and the washer outlet. The valve preferably has a fluid return to an inlet, of the pump, and the valve is operable to vent fluid to the pump return at a preset pressure setting to maintain a constant pressure delivery (at the preset pressure) to the washer outlet. A sensor is optionally associated with the bypass valve, or elsewhere in the fluid flow path, to detect a preset xe2x80x98low pressurexe2x80x99 condition and to initiate an auto shut off sequence for the pump on detection of the low pressure condition.